JP2021164377A - Controller for motor - Google Patents

Abstract

To provide a controller for a motor, the controller inhibiting the motor from rotating reversely while shortening a time required for stopping the motor.SOLUTION: A controller for a motor uses a position θ to convert a d-axis voltage command value Vd* and q-axis voltage command value Vq* to a U-phase voltage command value Vu*, V-phase voltage command value Vv*, and W-phase voltage command value Vw* when a torque command value T* is equal to or larger than zero or when the torque command value T* is smaller than zero and a rotation frequency ω is larger than a given rotation frequency; and brings the U-phase voltage command value Vu*, V-phase voltage command value Vv*, and W-phase voltage command value Vw* into zero when the torque command value T* is smaller than zero and the rotation frequency ω is equal to or smaller than the given rotation frequency.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device for an electric motor.

As a control device for a motor, there is a device that applies a negative torque to the motor when the motor is stopped to reduce the rotation speed of the motor relatively quickly. Patent Document 1 is a related technique.

By the way, when estimating the rotation speed of a motor using the current or voltage command value after removing the noise contained in the current flowing through the motor or the voltage command value with a filter, the estimation of the rotation speed is delayed due to the time constant of the filter. , The estimated number of revolutions may differ from the actual number of revolutions.

In addition, when the noise contained in the position of the rotor of the motor detected by a resolver or the like is removed by a filter and then the rotation number of the motor is calculated using that position, the calculation of the rotation number is delayed due to the time constant of the filter. , The calculated number of revolutions may differ from the actual number of revolutions.

Therefore, in the above control device, when estimating the rotation speed of the motor using the current or voltage command value from which noise has been removed by the filter, or when calculating the rotation speed of the motor using the position where the noise has been removed by the filter. And, when a negative torque is applied to the motor when the motor is stopped, the estimated or calculated rotation speed is not yet zero even though the actual rotation speed is already zero. There is a possibility that the actual number of revolutions will become a negative value by continuing to apply negative torque, that is, there is a possibility that the motor will rotate in the reverse direction.

Japanese Unexamined Patent Publication No. 5-284610

An object of one aspect of the present invention is to prevent the motor from rotating in the reverse direction while shortening the time required to stop the motor in the control device of the motor.

The motor control device according to the present invention includes a torque control unit that calculates a torque command value based on the difference between the motor rotation speed and the rotation speed command value, and the torque command value is a d-axis current command value and q. The first conversion unit that converts the shaft current command value, the second conversion unit that converts the current flowing through the motor into the d-axis current and the q-axis current depending on the position of the rotor of the motor, and the d-axis current and d-axis current. A current control unit that calculates the d-axis voltage command value so that the difference from the command value becomes small, and calculates the q-axis voltage command value so that the difference between the q-axis current and the q-axis current command value becomes small, and the torque. When the command value is zero or more, or when the torque command value is smaller than zero and the rotation speed is greater than a certain rotation speed, the d-axis voltage command value and the q-axis voltage command value depend on the position of the rotor. Is converted to the voltage command value corresponding to each phase of the motor, and when the torque command value is smaller than zero and the rotation speed is less than a certain rotation speed, the voltage command value corresponding to each phase of the motor is changed. It includes a third conversion unit that makes it zero, and a drive circuit that drives the motor based on the comparison result between the carrier and the voltage command value corresponding to each phase.

As a result, while applying negative torque to the motor when the motor is stopped, after the rotation speed drops to a certain speed, the torque is stopped from being applied to the motor and the actual rotation speed is calculated by the frictional force applied to the rotor. Since it can be lowered to zero, it is possible to prevent the motor from rotating in the reverse direction while shortening the time required to stop the motor.

Further, the motor control device according to the present invention determines the number of revolutions of the motor and the position of the rotor of the motor according to the d-axis current, the q-axis current, the d-axis voltage command value, and the q-axis voltage command value. It may be configured to include an estimation unit for estimation.

As a result, when the drive of the motor is controlled using the estimated rotation speed and position, it is possible to prevent the motor from rotating in the reverse direction while shortening the time required to stop the motor.

According to the present invention, in the control device for an electric motor, it is possible to prevent the electric motor from rotating in the reverse direction while shortening the time required for stopping the electric motor.

It is a figure which shows an example of the control device of the electric motor of an embodiment. It is a flowchart which shows an example of the operation of the coordinate conversion part. It is a figure which shows the relationship between the rotation speed and a torque command value. It is a figure which shows the modification of the control device of the electric motor of embodiment.

Hereinafter, embodiments will be described in detail based on the drawings.

FIG. 1 is a diagram showing an example of a control device for an electric motor according to an embodiment.

The control device 1 shown in FIG. 1 is, for example, a control device for driving an electric motor M (permanent magnet synchronous motor, etc.) mounted on a vehicle (electric forklift, plug-in hybrid vehicle, etc.), and is a control device for driving the inverter circuit 2. , The control circuit 3 is provided.

The inverter circuit 2 converts the DC power supplied from the power supply P into AC power to drive the motor M, and includes a capacitor C and switching elements SW1 to SW6 (IGBT (Insulated Gate Bipolar Transistor) or the like). , The current sensors Si1 and Si2 are provided. That is, one end of the capacitor C is connected to the positive electrode terminal of the power supply P and each collector terminal of the switching elements SW1, SW3, SW5, and the other end of the capacitor C is the negative electrode terminal of the power supply P and each of the switching elements SW2, SW4, SW6. It is connected to the emitter terminal. The connection point between the emitter terminal of the switching element SW1 and the collector terminal of the switching element SW2 is connected to the U-phase input terminal of the motor M via the current sensor Si1. The connection point between the emitter terminal of the switching element SW3 and the collector terminal of the switching element SW4 is connected to the V-phase input terminal of the motor M via the current sensor Si2. The connection point between the emitter terminal of the switching element SW5 and the collector terminal of the switching element SW6 is connected to the input terminal of the W phase of the motor M.

The capacitor C smoothes the voltage output from the power supply P to the inverter circuit 2.

The switching element SW1 is turned on when the pulse width modulation signal S1 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S1 is at a low level. The switching element SW2 is turned on when the pulse width modulation signal S2 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S2 is at a low level. The switching element SW3 is turned on when the pulse width modulation signal S3 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S3 is at a low level. The switching element SW4 is turned on when the pulse width modulation signal S4 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S4 is at a low level. The switching element SW5 is turned on when the pulse width modulation signal S5 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S5 is at a low level. The switching element SW6 is turned on when the pulse width modulation signal S6 output from the control circuit 3 is at a high level, and is turned off when the pulse width modulation signal S6 is at a low level.

When the switching elements SW1 to SW6 are turned on and off, respectively, the DC voltage output from the power supply P is converted into AC voltages Vu, Vv, and Vw whose phases differ by 120 degrees from each other. Then, the AC voltage Vu is applied to the U-phase input terminal of the motor M, the AC voltage Vv is applied to the V-phase input terminal of the motor M, and the AC voltage Vw is applied to the W-phase input terminal of the motor M. As a result, alternating currents Iu, Iv, and Iw whose phases differ from each other by 120 degrees flow through the motor M, and the rotor of the motor M rotates.

The current sensor Si1 is composed of a Hall element, a shunt resistor, and the like, and detects the alternating current Iu flowing in the U phase of the motor M and outputs it to the control circuit 3. Further, the current sensor Si2 is composed of a Hall element, a shunt resistor, and the like, and detects the alternating current Iv flowing in the V phase of the motor M and outputs it to the control circuit 3.

The control circuit 3 includes a storage unit 4, a drive circuit 5, and a calculation unit 6.

The storage unit 4 is composed of a RAM (Random Access Memory), a ROM (Read Only Memory), or the like, and stores a constant rotation speed or the like, which will be described later.

The drive circuit 5 is composed of an IC (Integrated Circuit) or the like, and outputs a U-phase voltage command value Vu *, a V-phase voltage command value Vv *, a W-phase voltage command value Vw *, and a carrier, which are output from the calculation unit 6. The comparison is performed, and the pulse width modulation signals S1 to S6 according to the comparison result are output to the respective gate terminals of the switching elements SW1 to SW6. The carrier wave is a triangular wave, a sawtooth wave (sawtooth wave), an inverse sawtooth wave, or the like.

For example, when the U-phase voltage command value Vu * is equal to or higher than the carrier, the drive circuit 5 outputs a high-level pulse width modulation signal S1 and a low-level pulse width modulation signal S2 to output a U-phase voltage command value. When Vu * is smaller than the carrier, the low level pulse width modulation signal S1 is output and the high level pulse width modulation signal S2 is output. Further, when the V-phase voltage command value Vv * is equal to or higher than the carrier, the drive circuit 5 outputs a high-level pulse width modulation signal S3 and a low-level pulse width modulation signal S4 to output a V-phase voltage command value. When Vv * is smaller than the carrier, the low level pulse width modulation signal S3 is output and the high level pulse width modulation signal S4 is output. Further, when the W-phase voltage command value Vw * is equal to or higher than the carrier, the drive circuit 5 outputs a high-level pulse width modulation signal S5 and a low-level pulse width modulation signal S6 to output a W-phase voltage command value. When Vw * is smaller than the carrier, the low-level pulse width modulation signal S5 is output and the high-level pulse width modulation signal S6 is output.

The calculation unit 6 is composed of a subtraction unit 7, a torque control unit 8, a torque / current command value conversion unit 9 (first conversion unit), and a coordinate conversion unit 10 (second conversion unit). ), The subtraction unit 11, the subtraction unit 12, the current control unit 13, the coordinate conversion unit 14 (third conversion unit), and the estimation unit 15. For example, when the microcomputer executes the program stored in the storage unit 4, the subtraction unit 7, the torque control unit 8, the torque / current command value conversion unit 9, the coordinate conversion unit 10, the subtraction unit 11, and the subtraction unit 12 , The current control unit 13, the coordinate conversion unit 14, the estimation unit 15, and the filters in the estimation unit 15 described later are realized.

The subtraction unit 7 calculates the difference Δω between the rotation speed command value ω * input from the outside and the rotation speed ω output from the estimation unit 15.

The torque control unit 8 obtains the torque command value T * by using the difference Δω output from the subtraction unit 7. For example, the torque control unit 8 corresponds to the rotation speed corresponding to the difference Δω by referring to the information stored in the storage unit 4 in which the rotation speed of the motor M and the torque of the motor M are associated with each other. The torque to be generated is obtained as the torque command value T *.

The torque / current command value conversion unit 9 converts the torque command value T * output from the torque control unit 8 into the d-axis current command value Id * and the q-axis current command value Iq *. For example, the torque / current command value conversion unit 9 stores information in the storage unit 4 in which the torque of the motor M and the d-axis current command value Id * and the q-axis current command value Iq * are associated with each other. The d-axis current command value Id * and the q-axis current command value Iq * corresponding to the torque corresponding to the torque command value T * are obtained with reference to.

The coordinate conversion unit 10 uses the alternating current Iu detected by the current sensor Si1 and the alternating current Iv detected by the current sensor Si2 to obtain the alternating current Iw flowing in the W phase of the electric motor M. The current detected by the current sensors Si1 and Si2 is not limited to the combination of the alternating currents Iu and Iv, and may be a combination of the alternating currents Iv and Iw or a combination of the alternating currents Iu and Iw. When the alternating currents Iv and Iw are detected by the current sensors Si1 and Si2, the coordinate conversion unit 10 obtains the alternating current Iu using the alternating currents Iv and Iw. When the alternating currents Iu and Iw are detected by the current sensors Si1 and Si2, the coordinate conversion unit 10 obtains the alternating current Iv using the alternating currents Iu and Iw.

Further, the coordinate conversion unit 10 uses the position θ (phase from the reference position of the rotor to the current position) estimated by the estimation unit 15 to convert the alternating currents Iu, Iv, and Iw into the d-axis current Id (weakening field). It is converted into a current component for generating magnetism) and a q-axis current Iq (current component for generating torque). For example, the coordinate conversion unit 10 converts the alternating currents Iu, Iv, and Iw into the d-axis current Id and the q-axis current Iq by using the transformation matrix C1 shown in the following equation 1.

Further, when the inverter circuit 2 is further provided with the current sensor Si3 for detecting the alternating current Iw flowing in the W phase of the motor M in addition to the current sensors Si1 and Si2, the coordinate conversion unit 10 is output from the estimation unit 15. The position θ may be used to convert the alternating currents Iu, Iv, and Iw detected by the current sensors Si1 to Si3 into the d-axis current Id and the q-axis current Iq.

The subtraction unit 11 calculates the difference ΔId between the d-axis current command value Id * output from the torque / current command value conversion unit 9 and the d-axis current Id output from the coordinate conversion unit 10.

The subtraction unit 12 calculates the difference ΔIq between the q-axis current command value Iq * output from the torque / current command value conversion unit 9 and the q-axis current Iq output from the coordinate conversion unit 10.

The current control unit 13 controls the d-axis voltage command value Vd * and the q-axis voltage command value Vq * by PI (Proportional Integral) control using the difference ΔId output from the subtraction unit 11 and the difference ΔIq output from the subtraction unit 12. Is calculated. For example, the current control unit 13 calculates the d-axis voltage command value Vd * using the following formula 2 and calculates the q-axis voltage command value Vq * using the following formula 3. Kp is a constant of the proportional term of PI control, Ki is a constant of the integration term of PI control, Lq is the q-axis inductance of the coil constituting the motor M, and Ld is the d-axis inductance of the coil constituting the motor M. Let ω be the number of revolutions output from the estimation unit 15, and Ke be the induced voltage constant.

d-axis voltage command value Vd * = Kp × difference ΔId + Ki × ∫ (difference ΔId) −ωLqIq ・ ・ ・ Equation 2

q-axis voltage command value Vq * = Kp × difference ΔIq + Ki × ∫ (difference ΔIq) + ωLdId + ωKe ・ ・ ・ Equation 3

That is, the current control unit 13 calculates the d-axis voltage command value Vd * so that the difference ΔId between the d-axis current Id and the d-axis current command value Id * becomes small, and the q-axis current Iq and the q-axis current command value. The q-axis voltage command value Vq * is calculated so that the difference ΔIq from Iq * becomes small.

The coordinate conversion unit 14 rotates when the torque command value T * output from the torque control unit 8 is zero or more, or when the torque command value T * is smaller than zero, and the rotation is output from the estimation unit 15. When the number ω is larger than a constant rotation speed, the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are set to the U-phase voltage command values Vu * and V by using the position θ output from the estimation unit 15. It is converted into the phase voltage command value Vv * and the W phase voltage command value Vw *. For example, the coordinate conversion unit 14 uses the transformation matrix C2 shown in the following equation 4 to convert the d-axis voltage command value Vd * and the q-axis voltage command value Vq * into the U-phase voltage command value Vu * and the V-phase voltage command value. Convert to Vv * and W phase voltage command value Vw *. The constant rotation speed is, for example, a rotation speed less than 1% of the positive maximum value of the rotation speed ω.

Further, when the torque command value T * is smaller than zero and the rotation speed ω output from the estimation unit 15 is equal to or less than a certain rotation speed, the coordinate conversion unit 14 has a U-phase voltage command value Vu *, Set the V-phase voltage command value Vv * and the W-phase voltage command value Vw * to zero.

The estimation unit 15 uses the d-axis current Id and q-axis current Iq output from the coordinate conversion unit 10, and the d-axis voltage command value Vd * and q-axis voltage command value Vq * output from the current control unit 13. The rotation speed ω and the position θ are estimated. For example, the estimation unit 15 obtains the rotation speed ω using the voltage equation shown in the following equation 5, and obtains the position θ by multiplying the obtained rotation speed ω by a predetermined time (such as the operation clock of the calculation unit 6). .. In addition, R is a resistance component of the coil constituting the motor M, and p is a differential operator.

FIG. 2 is a flowchart showing an example of the operation of the coordinate conversion unit 14.

First, the coordinate conversion unit 14 rotates when the torque command value T * is zero or more (step S1: No) or when the torque command value T * is smaller than zero and is output from the estimation unit 15. When the number ω is larger than a constant rotation speed (step S1: Yes, step S2: No), the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are used by using the position θ output from the estimation unit 15. Is converted into a U-phase voltage command value Vu *, a V-phase voltage command value Vv *, and a W-phase voltage command value Vw * (step S3).

On the other hand, in the coordinate conversion unit 14, when the torque command value T * is smaller than zero and the rotation speed ω output from the estimation unit 15 is equal to or less than a certain rotation speed (step S1: Yes, step S2: Yes), the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * are set to zero (step S4). As a result, the duty ratios of the pulse width modulation signals S1 to S6 can be set to zero, so that the inverter circuit 2 can be stopped and the motor M can be prevented from applying torque.

That is, when the coordinate conversion unit 14 drives the motor M by power running control, or when the motor M is driven by regenerative control, and when the estimated rotation speed ω is relatively large, the motor Continue to apply torque to M.

On the other hand, the coordinate conversion unit 14 stops applying torque to the motor M when the motor M is driven by regenerative control and when the estimated rotation speed ω becomes relatively small. As a result, the rotor rotates by inertia, so that the actual rotation speed can be gradually reduced due to the frictional force applied to the rotor or the like.

FIG. 3 is a diagram showing the relationship between the rotation speed ω and the torque command value T *. The horizontal axis of the two-dimensional coordinates shown in FIG. 3 indicates the rotation speed ω, and the vertical axis indicates the torque command value T *. Further, + ω indicates a positive maximum value of the rotation speed ω, + T * indicates a positive maximum value of the torque command value T *, and −T * indicates a negative maximum value of the torque command value T *. Further, it is assumed that the rotation speed ω and the torque command value T * change within the broken line frame passing through + ω, + T *, and −T *.

For example, the rotation speed command value ω * suddenly changes to zero from the state where the rotation speed ω and the torque command value T * are positive values (the state where the motor M is driven by power running control), and the motor M changes. Suppose a transition to a stopped state.

In this case, the torque control unit 8 changes the torque command value T * to a negative maximum value as shown by the solid arrow shown in FIG. As a result, a negative torque can be applied to the motor M, that is, the motor M can be driven by regenerative control. Therefore, the motor is driven by the frictional force applied to the rotor without applying a negative torque to the motor M. The actual number of revolutions can be reduced faster than when M is stopped.

Generally, when the rotation speed ω is estimated using the d-axis current Id, the q-axis current Iq, the d-axis voltage command value Vd *, and the q-axis voltage command value Vq * from which noise has been removed by the filter, the filter is used. The estimation of the rotation speed ω is delayed due to the time constant. In particular, when the rotation speed ω is relatively small, the estimation of the rotation speed ω tends to be delayed. Therefore, when the torque command value T * changes from the negative maximum value to zero as the estimated rotation speed ω approaches zero, it is estimated even though the actual rotation speed is already zero. If the calculated rotation speed ω is not yet zero, negative torque will continue to be applied to the motor M, and the actual rotation speed may become a negative value, as shown by the broken arrow in FIG. That is, the motor M may rotate in the reverse direction.

Therefore, in the control device 1 of the present embodiment, when the torque command value T * is smaller than zero and the rotation speed ω output from the estimation unit 15 is a constant rotation speed or less, the U-phase voltage command value. The configuration is such that Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * are set to zero. As a result, when the motor M is stopped, a negative torque is applied to the motor M to reduce the rotation speed ω to a constant rotation speed, and then the torque is stopped to be applied to the motor M and the frictional force applied to the rotor is actually used. Since the number of rotations of the motor motor M can be reduced to zero, it is possible to prevent the motor motor M from rotating in the reverse direction while shortening the time required to stop the motor motor M.

The present invention is not limited to the above embodiments, and various improvements and changes can be made without departing from the gist of the present invention.

<Modification example>
FIG. 4 is a diagram showing a modified example of the control device 1 of the embodiment. In FIG. 4, the same components as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The control device 1 shown in FIG. 4 differs from the control device 1 shown in FIG. 1 in that the rotation speed calculation unit 16 is provided instead of the estimation unit 15. It is assumed that the electric motor M includes an electric angle detection unit Sp (resolver or the like) that detects the position θ of the rotor and outputs the detected position θ to the control circuit 3. Further, in the control device 1 shown in FIG. 4, for example, it is assumed that the calculation of the rotation speed ω is delayed by the time constant of the filter that removes the noise included in the position θ input to the rotation speed calculation unit 16. Therefore, even though the actual rotation speed is already zero, the calculated rotation speed ω is not yet zero, so that negative torque is continuously applied to the motor M and the actual rotation speed is negative. There is a possibility that the value will be reached, that is, the motor M may be rotated in the reverse direction.

The rotation speed calculation unit 16 calculates the rotation speed ω using the position θ detected by the electric angle detection unit Sp. For example, the rotation speed calculation unit 16 obtains the rotation speed ω by dividing the position θ by a predetermined time (such as the operation clock of the calculation unit 6).

Further, the subtraction unit 7 shown in FIG. 4 calculates the difference Δω between the rotation speed command value ω * input from the outside and the rotation speed ω output from the rotation speed calculation unit 16.

Further, the coordinate conversion unit 14 shown in FIG. 4 has a torque command value T * output from the torque control unit 8 of zero or more, or a torque command value T * smaller than zero, and the number of rotations. When the rotation speed ω output from the calculation unit 16 is larger than a constant rotation speed, the d-axis voltage command value Vd ** and the q-axis voltage command value Vq * are used by using the position θ detected by the electric angle detection unit Sp. * Is converted into a U-phase voltage command value Vu *, a V-phase voltage command value Vv *, and a W-phase voltage command value Vw *.

Further, the coordinate conversion unit 14 shown in FIG. 4 rotates when the torque command value T * output from the torque control unit 8 is smaller than zero and the rotation speed ω output from the rotation speed calculation unit 16 is constant. If it is less than or equal to the number, the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * are set to zero.

As described above, the control device 1 shown in FIG. 4 is the same as the control device 1 shown in FIG. 1 when the torque command value T * is smaller than zero and the rotation speed ω is equal to or less than a certain rotation speed. , U-phase voltage command value Vu *, V-phase voltage command value Vv *, and W-phase voltage command value Vw * are set to zero. As a result, when the motor M is stopped, a negative torque is applied to the motor M to reduce the rotation speed ω to a constant rotation speed, and then the torque is stopped to be applied to the motor M and the frictional force applied to the rotor is actually used. Since the number of rotations of the motor motor M can be reduced to zero, it is possible to prevent the motor motor M from rotating in the reverse direction while shortening the time required to stop the motor motor M.

1 Control device 2 Inverter circuit 3 Control circuit 4 Storage unit 5 Drive circuit 6 Calculation unit 7 Subtraction unit 8 Torque control unit 9 Torque / current command value conversion unit 10 Coordinate conversion unit 11 Subtraction unit 12 Subtraction unit 13 Current control unit 14 Coordinate conversion Unit 15 Estimating unit 16 Rotation speed calculation unit

Claims (2)

A torque control unit that calculates the torque command value based on the difference between the rotation speed of the motor and the rotation speed command value,
A first conversion unit that converts the torque command value into a d-axis current command value and a q-axis current command value, and
A second conversion unit that converts the current flowing through the motor into a d-axis current and a q-axis current depending on the position of the rotor of the motor, and
The d-axis voltage command value is calculated so that the difference between the d-axis current and the d-axis current command value becomes small, and the q-axis voltage so that the difference between the q-axis current and the q-axis current command value becomes small. The current control unit that calculates the command value and
When the torque command value is zero or more, or when the torque command value is smaller than zero and the rotation speed is larger than a constant rotation speed, the d-axis voltage command value and the q are depending on the position. When the shaft voltage command value is converted into the voltage command value corresponding to each phase of the motor, the torque command value is smaller than zero, and the rotation speed is equal to or less than the constant rotation speed, the motor A third converter that sets the voltage command value corresponding to each phase to zero,
A drive circuit that drives the motor based on the comparison result between the carrier wave and the voltage command value corresponding to each phase of the motor, and
Motor control device. The motor control device according to claim 1.
A control device for an electric motor, comprising an estimation unit that estimates the rotation speed and the position based on the d-axis current, the q-axis current, the d-axis voltage command value, and the q-axis voltage command value.

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